Process of reducing the viscosity characteristics of nitrocellulosic materials



Patented F ch.- 9, 1926.

1,512,249- UNITED STAT- s P T T orrlcs.

SAMUEL E. SHEPPARD AND Id EON w. EBEBLIN, OF ROCHESTER, NEW YORK, AS?

SIGNOBS 'IO EASTMAN KODAK COMPANY,

TION OFJTEW YOBK..

enemies or ammonia THE vrscosrrr ename'rnmsrres or 'm'rnocnLLuLosIo OFROCHESTER, NEW YORK, A CORPORA- unranms.

No Drawing.

To all whom it may concern:

Be it known that we, SAMUEL E. sum- 1 certain new and useful Imrovements in at room temperature, without Processes-of Reducing theiscosity Characteristics of Nitrocellulosic Materials, of which the.following is a full, clear, and exact specification. c

This invention relates to processes for treating nitrocellulosicmaterials in such a way as to reduce the viscosity characteristicsthereof. One object of the invention is to provide a safe, simple andrelatively inexpensive process for treatin such materials in order toobtain the desired lower viscosity characteristics. Anotherobject of theinvention is to provide a process in which the change in the viscositycharacteristics can be eifec-ted with suflicient rapidity the necessityof using heating operations. A further object of the invention is toprovide such a processin which the material is readily purified byreason of the practical neutrality of the treating bath. Other objectswill hereinafter appear. a

In certain industries it is desirable to use solutions of nitrocellulosewhich-have a high concentration of the latter and yet "have a lowviscosit It is desirable to provide a safe and re ativel inexpensiveprocess for convertingthe hig -viscosity types of nitrocellulose, whichare roducedin large quantities for. many in ustrial purposes, intonitrocelluloses which have low viscosity characteristics and cantherefore, be-made into solutions of the above described type. We havefound that a process having these desirable eflects can be carried outby treatin nitrocellulosic material with a peroxi e' solution,preferably one. which is substantially neutral. The action proceeds withuseful rapidity at room temperature and varies with the concentration ofthe peroxide, which is usually hydrogen peroxide. The treatment isapplicable to nitrocellulose in-its various forms and its variousassociations.

Application and June 15, 1925. Serial m. 37,405.

Weshall now describe. by Way of illustra tion as ecific example of ourinvention, but it will be understood that the latter is not limited tothe details, thus given,except as indicated in-the appended claims. INitrocellulosic material, such as pyroxylin waste or photographic filmscrap, from which gelatinous material has preferably" been removed,- oreven the orig nal nitrocellulose fibers, are

placed, while in comminuted condition in a 3% .aqueous solution ofhydrogen peroxide of substantial neutrality at ,room' temperature. It isallowed to remain in this'bath at room temperature, indicate that thedesired lowering-of viscosity has taken place. While the time may varygreatly, we have found that. a treat. ment of 24 hours at roomtemperature, under the above described conditions, produces a until theusual tests 1 very marked reduction in the viscosity charl' acteristicsof the nitrocellulose even when the latter is associated with highboiling organic compounds like cohol and soforth.

After the action is completed, the bath is drainedoff from thenitrocellulosic material, and the latter is washed.

approximate neutrality of the bath, it is very which comprises actingthereon with a bath camphor, butyl al- 7 I By reason ofthe' A neutralsolution of the ordinary of a peroxide, until its viscositycharacte'risticsare' lowered. i

2. The process of treating nitrocellulose which comprises acting thereonwith a substantially neutral aqueous bath of-a peroxide until thenitrocellulose are reduced.

3. The which comprises acting thereon with a subviscositycharacteristics of the process of treatinganitrocellulosei easy topurify the material by washing, there b teristics of the nitrocelluloseare reduced.

4. The process of treating nitrocellulose which comprises immersing thesame in -a substantially neutral aqueous bath of hydrogen peroxide atroom temperature until the viscosity characteristics of thenitrocellulose are. reduced.

5. The process of treating nitrocellulose which comprises acting thereonwith a-substantially neutral aqueous bath of hydrogen peroxide, untilthe viscosity characteristics of the nitrocellulose are lowered, andwashing said bath from said material.

(5. The process of treating colloidized same with a bath containingperoxide until the viscosity characteristics of the nitrocellulose arereduced.

7. The process of treating solid colloidized nitrocellulose associatedwith a high boiling organic compound, which comprises acting on thesame, while in a condition having a large surface relative to its mass,with a substantially neutral aqueous solution of hydrogen peroxide untilthe viscosity characteristics of the nitrocellulose are reduced. Signedat Rochester, New York, this 11th day of June 1925.

SAMUEL E. SHEPPARD. LEON W. EBERLIN.

